1. Field of the Invention
The present invention relates to trawls and, more particularly, to an improved shrimp trawl using a controlled cage which is operated at the surface so that marine life being caught can be continually viewed and unwanted fish, marine life, and small shrimp can be released unharmed during trawling.
2. General Background
In the fishing/shrimping industry, it is well known to employ an elongated net having an opening at one end and a closed tail at the other end portion when trawling for shrimp. Shrimp trawls are elongated nets which are generally pulled behind a vessel. The nets can be pulled along the sea bottom, at various depths, and also at the water surface. Trawling at the water surface is usually done at night because shrimp will feed at the water surface at night. They usually remain at the water bottom during daylight hours.
Examples of a typical underwater type shrimp trawl can be seen in U.S. Pat. No. 2,940,980 entitled "Commercial Shrimp Net" issued to J. T. Worcester. Another example of a typical underwater trawl is U.S. Pat. No. 2,890,543 issued to R. O. Mitchell entitled "Trawl Net Attachment."
An example of a top water shrimping device is U.S. Pat. No. 1,498,760 issued to P. M. Skrmetti entitled "Floating Trawl" issued June 24, 1924.
Problems exist with prior type shrimp trawls which render them useless or less than efficient in the harvesting of shrimp. One of the problems with the conventional shrimp trawl is that the user cannot view the net during harvesting. Rather the fisherman pulls the net for long periods of time; the net is then raised to examine what has been caught. Unfortunately, a good bit of the aquatic life caught in the net is not harvestable shrimp of sufficient size. Some aquatic life caught in the net is not shrimp at all. For example, non-shrimp aquatic life such as small fish, crabs, and the like can be caught in the net. Undersized shrimp which are not suitable for harvesting can be caught in the net. Much of this aquatic life is killed by the trawling process when these life forms are caught in the net and dragged for long periods of time. This "blind" system results in a tremendous waste of marine life, and extra work for the shrimper since the killed "trash" must be sorted from the shrimp.
Another problem of prior type trawls is the handling of the trawl itself. Usually the net is an elongated structure which is pulled a distance behind the boat. In order to harvest the shrimp which are caught in the net, the net must be pulled up into the boat without losing the shrimp which have been caught. Trawls are awkward and difficult to pull into the boat. This job is both arduous and time consuming. In very rough seas, it can be dangerous. A sorting process must also be used to determine which of the catch is to be retained and which of the catch is to be discarded.
3. General Discussion of the Present Invention
The present invention provides a solution to the above discussed problems by providing a shrimp trawl cage apparatus which can be used with a vessel, when preferably two nets are supported at the water surface by the vessel on port and starboard sides respectively. The net provides a frame supporting the net inlet opening and the other end of the net defines a tail which is also open. The tail connects to and communicates with a cage which is supported in a partially submerged position by the vessel. The cage provides an inlet which is fed by the tail of the net. The cage is an enclosed structure having a number of cage surfaces which are connected at their edges to form an enclosure confining the shrimp entering the cage. A rear gate portion of the cage has a removable opening which can be closed or opened so that shrimp which enter the cage can be selectively discharged from the cage. The cage has an open top so that shrimp to be harvested can be removed, even during trawling.
Mounting brackets affix each of the net and cage assemblies to the vessel in a lateral position with respect to and generally parallel to the vessel. The brackets provide an adjustability for moving the cage with respect to the net so that the net can be tightened or slackened by movement of the cage with respect to the net. The adjustability is preferably in the form of an elongated rail affixed to the vessel gunwhale. Cage brackets slideably affix the cage to the rail so that the rail can function as an adjustable support between the cage and the vessel. The cage can thus slide longitudinally with respect to the net so that forward movement of the cage slackens the net and rearward movement of the cage tightens the net. The forward slackened position would be assumed during unloading of the cage while the rearward tightened position of the cage would be the trawling position. The cage would preferably pivot from its position at the water surface upwardly about the rail into the vessel for unloading purposes.